linux-kernel - [PATCH 6/8] arm64: dts: qcom: msm8939-samsung-a7: Add NFC

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Message-ID: <20230622020530.65845-1-linmengbo0689@protonmail.com>
Date:   Thu, 22 Jun 2023 02:05:39 +0000
From:   "Lin, Meng-Bo" <linmengbo0689@...tonmail.com>
To:     linux-kernel@...r.kernel.org
Cc:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Stephan Gerhold <stephan@...hold.net>,
        Nikita Travkin <nikita@...n.ru>, linux-arm-msm@...r.kernel.org,
        devicetree@...r.kernel.org, ~postmarketos/upstreaming@...ts.sr.ht
Subject: [PATCH 6/8] arm64: dts: qcom: msm8939-samsung-a7: Add NFC

The Galaxy A7 has a NXP PN547, which is supported
by the nxp-nci-i2c driver in mainline. It seems to detect NFC tags
using "nfctool" just fine, although more testing is difficult given
there seem to be very few useful applications making use of the
Linux NFC subsystem.

Note that for some reason Samsung decided to connect the I2C pins
to GPIOs where no hardware I2C bus is available, so we need to
fall back to software bit-banging with i2c-gpio.

Signed-off-by: Lin, Meng-Bo <linmengbo0689@...tonmail.com>
---
 .../boot/dts/qcom/msm8939-samsung-a7.dts      | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts b/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
index 271dcea6da94..dcbc8a97ce63 100644
--- a/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
+++ b/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
@@ -92,6 +92,32 @@ battery@35 {
 		};
 	};
 
+	i2c-nfc {
+		compatible = "i2c-gpio";
+		sda-gpios = <&tlmm 0 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+		scl-gpios = <&tlmm 1 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+
+		pinctrl-0 = <&nfc_i2c_default>;
+		pinctrl-names = "default";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		nfc@2b {
+			compatible = "nxp,pn547", "nxp,nxp-nci-i2c";
+			reg = <0x2b>;
+
+			interrupt-parent = <&tlmm>;
+			interrupts = <21 IRQ_TYPE_EDGE_RISING>;
+
+			enable-gpios = <&tlmm 116 GPIO_ACTIVE_HIGH>;
+			firmware-gpios = <&tlmm 49 GPIO_ACTIVE_HIGH>;
+
+			pinctrl-0 = <&nfc_default>;
+			pinctrl-names = "default";
+		};
+	};
+
 	i2c-sensor {
 		compatible = "i2c-gpio";
 		sda-gpios = <&tlmm 84 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
@@ -292,6 +318,29 @@ muic_int_default: muic-int-default-state {
 		bias-disable;
 	};
 
+	nfc_default: nfc-default-state {
+		irq-pins {
+			pins = "gpio21";
+			function = "gpio";
+			drive-strength = <2>;
+			bias-pull-down;
+		};
+
+		nfc-pins {
+			pins = "gpio49", "gpio116";
+			function = "gpio";
+			drive-strength = <2>;
+			bias-disable;
+		};
+	};
+
+	nfc_i2c_default: nfc-i2c-default-state {
+		pins = "gpio0", "gpio1";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
 	sdc2_cd_default: sdc2-cd-default-state {
 		pins = "gpio38";
 		function = "gpio";
-- 
2.39.2